352_fuchsshaftfurnaces

Technology Is Our Trademark

VAI/FUCHS Steelmaking Technology

FUCHS Shaft FurnacesThe POWER, The PERFORMANCE, The PROFIT

VOEST-ALPINE Industrieanlagenbau

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The Leading Suppliersof Electric Arc Furnaces!

Headquarters and Steelmaking Background of VAI

Linz, Austria

VAI at a Glance

VAI, an Austrian based company of the VA Technologie AG

group, is one of the world’s leading engineering and plant

building companies for the international iron and steel industry.

With a dedicated staff of nearly 4000 engineers, specialists

and support personnel, the company offers the complete

spectrum of iron and steelmaking technologies. To date, VAI

has successfully engineered and completed more than 800

major industrial projects in some 80 countries.

With its company headquarters situated in the midst of an in-

tegrated steel works, VAI is unique in that it has at its disposal

in-house operational, process and metallurgical know how.

These assets, coupled with our broad international experience,

turn-key capability, professional project management and

dedication to excellence, are the factors which ultimately con-

tribute to the success of our customers.

FUCHS at a Glance

FUCHS is the world leader in the design and manufacture of

electric arc furnaces, including all related electric steelmaking

facilities. Founded in 1969, the headquarters of FUCHS is lo-

cated in Baden-Würtemberg, Germany. The company has

since expanded to include engineering, manufacturing and

sales centers in the United States, Mexico, United Kingdom

and in South Africa. Today, FUCHS has a staff of more than

600 employees worldwide.

Pioneering developments by FUCHS in the field of electric

steelmaking include the first water-cooled panels and roofs for

electric arc furnaces, current conducting electrode arms and

other unique energy saving solutions such as shaft technology

for scrap preheating. Outstanding and innovative develop-

ments include the world’s first double shaft furnace, the finger

shaft furnace as well as the twin shell furnace concept.

Headquarters of FUCHS

Willstätt-Legelshurst, Germany

Serving the Steelmaking IndustryThrough Technology

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VAI/FUCHS Steelmaking TechnologyVAI/FUCHS Steelmaking Technology

The 95 t Single Shaft DC Furnace at North Star Steel, Kingman, AZ, USA

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For the Ultimate inShaft Furnace Technology

Features and Highlights

The shaft furnace was developed by FUCHS in the late

1980s. This development was in response to the market chal-

lenges for minimum conversion costs, maximized output and

environmental compliance. Featuring the utilization of the fur-

nace off-gases during the heat cycle for the preheating of

scrap in a shaft, this technology is the most advanced EAF

process available on the market today.

■ AC technology or DC technology

(latter with VAI Fin-Type Anode System)

■ Self-supporting, water-cooled roof and shaft

■ Bottom tapping systems

■ Current conducting electrode arms

■ Side wall panels with steel & copper pipes

■ High-velocity copper panels and burner boxes

■ Side wall and shaft burners

■ Supersonic lance manipulator for oxygen and carbon

injection (side wall or slag door installation)

■ Oxygen injection for efficient post-combustion

Shaft Furnace References Worldwide as per 1997

(Single, Double and Finger Shaft)

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Schematic Diagram of a

FUCHS Shaft Furnace

HoodBurners

ShaftBurners

Injectors

ShellBurners

Injectors

MovableCollar

PC ChamberBurners T2

T1

Temperature Monitor

Gas AnalyzerCO, CO2, 02

2 Water Cooled Probeswith Heated Filter

One Sampling Per Purging

Post-CombustionChamber

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The 90 t Single Shaft AC Furnace at ZhangjiagangSheen Faith Steel, People´s Republic of China(viewed from the tapping side)

MAIN BENEFITS

■ Up to 100% scrappreheating

■ Up to 120 kWh/t liquid steelelectrical energy savings

■ Approx. 40% reducedflicker factor

■ Up to 15% reducedelectrode consumption

■ Up to 2% increase ofmetallic yield

■ Up to 25% lower dustemissions

■ Up to 20% productivityincrease


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Electrical Energy Consumption: 330 kWh/t

10 20 30 40 50 TIME [min]

Tap

pin

g

Tap

hole

Ref

illin

g

Cha

rge

Bas

ket

No

. 1 a

nd 2

Del

ays

AC

TIV

E P

OW

ER

[M

W]

0

SINGLE SHAFT FURNACE / 95 t Tapping Weight(Input Material: 100% Scrap, Consumption Figures in Tons of Liquid Steel)

60

50

40

30

20

10

0

Charge Basket No. 3 Sampling/Temperature

Scrap Melting102 t scrap

SteelRefining

Single Shaft Furnace

The Single Shaft Furnace (SSF) was designed to melt a

charge mix containing at least 80% scrap. More than half of

the scrap charge is preheated in the shaft. A typical heat

A Pioneering Development in Electric Steelmaking

cycle is characterized by a 35 - 40 minute power-on-time and

by a 10 - 15 minute power-off time. Depending on the scrap

density, 2 or 3 baskets are charged per heat.

Operational Diagram of a Single Shaft Furnace

A Pioneering Development in Electric Steelmaking

Typical Consumption, Performance Data and

References of Single Shaft Furnaces

References:■ Co-Steel Sheerness (Sheerness, United Kingdom)■ EGE-Metal (Aliaga, Turkey)■ Zhangjiagang Sheen Faith Steel (Zhangjiagang, PR China)■ North Star Steel (Kingman, AZ, USA)

The 95 t Single Shaft DC Furnace at

North Star Steel, Kingman, AZ, USA

100% Scrap:

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The 90 t Single Shaft AC Furnace at Zhangjiagang, Sheen Faith SteelPeople´s Republic of China


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The production output of a double shaft furnace meets therequirements of both a high capacity producer of long products as well as

those of a high quality flat producer where thin slabcasting technology is applied.

The outstanding advantage of the Double Shaft Furnace

(DSF) is that the power-off time can be reduced from 10 - 15

minutes to less than 2 minutes per heat! Two identical shaft

furnaces (Twin Shell Arrangement) are positioned next to

each other and are serviced by a single set of electrode arms.

Melting and refining is carried out in one furnace while the

second inactive furnace is being tapped and subsequently

charged with scrap.

Double Shaft Furnace

PERFORMANCEto the Power of 2!

References:

■ SAM, Montereau, France■ ARES, Esch-Schifflange, Luxembourg■ North Star - BHP, Delta, Ohio, USA

Computer Model of the

FUCHS Double Shaft Furnace


References of Double Shaft Furnaces

Because no waiting time for charging of the second basket

into the inactive furnace is necessary, 100% of the charge

mix can be preheated with the side wall burners.

Once the desired steel analysis and tapping temperature has

been achieved in the active furnace, the electrodes are then

moved to the other furnace. A new heat cycle commences

and the result is a power-off time of less than 2 minutes and

a power utilization which exceeds more than 94%.

Reduce Your Power-off Time toLess Than Two Minutes!

100% Scrap:

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The 95 t Double Shaft AC Furnace at SAM, Montereau, France


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The Finger Shaft Furnace (FSF) features a unique scrap re-

taining system (so-called finger system) in the lower shaft

section for the preheating of scrap by the furnace off-gas

during a heat cycle. In this way the full potential of the hot off-

gases can be utilized, meaning a maximum of energy savings

Finger Shaft Furnace

Ideal for 100% Scrap Preheating!

1. 100% of the scrap is charged through the shaft by

means of a scrap basket or belt conveyor.

2. During the refining phase of the previous heat the first

batch of the next heat is charged to the shaft onto the

closed fingers for preheating.

3. Hot off-gases and energy from post-combustion

preheats the charged material. After the previous heat

is tapped, the fingers are opened and the preheated

charge descends into the furnace vessel.

4. The next batch, already in the waiting position, is

immediately charged through the shaft onto the

Outline of an Operational Cycle

References:■ HYLSA, Monterrey, Mexico■ Cockerill-Sambre, Charleroi, Belgium■ Stahl Gerlafingen AG, Gerlafingen, Switzerland■ Birmingham Steel, Memphis, USA■ Natsteel, Singapore■ Megasteel, Klang, Malaysia (2x)■ Guangzhou Zhujiang Steel, Guangzhou, PR China■ Anyang Iron and Steel Co., Anyang, PR China■ HYLSA, Puebla, Mexico■ Severstal AG, Cherepovets, Russia■ Suez Steel Company, Suez, Egypt■ Nervacero, S.A, CELSA Group, Bilbao, Spain■ Chaparral, Midlothian, Texas, USA■ North Star, Youngstown, USA■ Aristrain, Olaberria, Spain


References of Finger Shaft Furnaces

View of the Fingers in a Typical

Finger Shaft Furnace

and productivity. Another outstanding feature of this furnace

type is its high flexibility with respect to the charge materials

(scrap, DRI, HBI, iron carbide, hot metal and pig iron), allow-

ing for the production of highest quality steel grades, includ-

ing flat products.

preheated batch as the fingers are kept open position.

5. Once the scrap has melted and the shaft is empty of

scrap, the fingers are closed again and the first batch

of the next heat is charged into the shaft for

preheating.

The result is that 100% of the shaft charge is preheated.

Finger Shaft Furnace Technology is also highly suitable for

the charging of DRI or hot metal directly to the furnace vessel

while still being able to utilize the hot off-gases for the

preheating of the remainder of the scrap.

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The 135 t Finger Shaft DC Furnace at HYLSA, Monterrey, Mexico


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FUCHS offers flexible upgrading packages which allow any

existing EAF with a capacity exceeding 60 tons heat size to

be economically modified to a Finger Shaft Furnace. The

main furnace components of the existing furnace, i.e. the

power supply, the furnace frame, electrode gantry, electrode

arms and the lower furnace shell remain unchanged. The

upper furnace shell and furnace roof are adapted for the

post-installation of the shaft with scrap retaining fingers.

Upgrade Your FurnaceWith a FUCHS Shaft

- FUCHS Optimized Retrofit ShaftThe Upgrading Solution to Maximize Your Furnace Performance!

Depending on the site conditions, (furnace bay height, space

availability, logistics for material handling, etc.), the furnace is

charged using either baskets or a conveyor belt system. In-

stallation can be carried out quickly and with a minimum of

interruption in ongoing production. The cost advantage of

minimized production costs in combination with a substan-

tially increased furnace output mean a highly attractive return

on investment (ROI) for electric steel producers.

Off-gas Hood

Current Conducting Electrode Arm(s)

Roof

Structure

Lift/Drive Unit

Shell

Tilt FramePlatform

Gantry

Shaft/Fingers

ScrapConveyor Belt

Existing EquipmentNew Equipment

FEATURES & BENEFITS:

■ Feasible for all AC and

DC furnaces exceeding

60 t heat size

■ Furnaces from any

supplier can be

upgraded

■ 5 -10% boost of active

power input with same

power supply

■ Low investment costs

through maximum use

of existing equipment

■ Only 1 month furnace

shutdown required for

complete installation

ORS

ORS

ORS

■ SAVINGS POTENTIALOF UP TO USD 20 PERTON OF STEEL!

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The POWER, The PERFORMANCEAnd The PROFIT!

FUCHS Shaft Furnace Technology stands for maximized

furnace output and impressive cost savings. To calculate

your approximate production costs per ton of steel,

or to compare your current EAF steelmaking costs with

those that can be achieved using a FUCHS Finger Shaft

Furnace, just use the enclosed FSF Cost Calculator.


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